Multi-stage presses



March 7, 1961 w. HUETTER 2,973,790

MULTL-STAGE PRESSES Filed April 23, 1959 2 Sheets-Sheet 2 III i'l III -Aviwmn W/LL HUEJ'IER A 1 TQQRNE ys United States Patent MULTI-STAGEPRESSES Will Huetter, Kreteld, Germany, assignor to Herbert van Huellenand Alfred van Huellen, trading as the firm NiederrheinischeMaschinenfabrik Becker and van Huellen, Krefeld, Germany Filed Apr. 23,1959, Ser. No. 832,875 1 Claim. (Cl. 144-281) The invention relates to apress, more particularly a multi-stage press having a hood for leadingaway noxious corrosion inducing gases and vapours which emerge from thepress space particularly when opening the press.

With presses of this kind, which are intended for the production ofveneer plates, the press abutments are usually provided with a coolingplate built in front thereof, which is connected by means of a gratewith a heating plate. Even if such a hood is joined to a conduitconnected to a chimney or a suction fan and hence subjected to a reducedpressure, a portion of the noxious gases and vapours, which on openingthe press rise upwardly, flows unavoidably into the grate chamberbetween the cooling and heating plates fixed to the upper pressabutment. It mustbe borne in mind moreover, that these two plates andthe grate disposed therebetween, taken together, are stretched outsomewhat after the manner of a bellows when the pressure ceases andcorrespondingly enlarges the grate space. In this chamber a certainlowering of pressure occurs, as the grate space enlarges, which favoursthe induction of the noxious gases and vapours. The consequence of thisis a relatively rapid destruction of the grate due to the corrosion. Thegrate must then be exchanged for a new grate with a correspondingly longstoppage of the press.

An object of the invention is to prevent positively, in a simple manner,the penetration of noxious gases and vapours into the grate spacebetween cooling and heating plates.

The multi-stage press comprises a cross beam having an upper horizontalmember and a lower horizontal member spaced from said upper member, themembers having apertures, a plurality of spaced vertical wallsconnecting the members and forming passages therewith, a cooling platefixed to said lower member. The cooling plate is provided with aplurality of perforations communicating with the apertures in the lowermember. A heating plate spaced from the cooling plate is provided, as isa grate securing the heating plate to the cooling plate and forming agrate space therebetween. The grate has notches communicating the gratespace with the passages.

in the crossbeam through the perforations in the cooling plate. Thereare provided conduit, means connected with the apertures in the uppermember for introducing compressed air into the passages and into thegrate space. A gas discharge hood is disposedabove the crossbeam forwithdrawing noxious gases and is provided with an exit duct. Thepressure of compressed air prevents noxious gases from penetrating intothe grate space.

The invention will be described further, by way of example, withreference to the accompanying drawings, in which:

Fig. 1 is a partial vertical section through the upper partof amultiple-stage press; and

Patented Mar. 7, 1961 Fig. 2 is a plan of the grate which is installedbetween i can preferably be connected to a flue or to a suction fan.

In addition to the previously described known press construction thereis provided a conduit 8 equipped with a throttle or blocking oii member7. This conduit conducts a compressed gas and passes through thedischarge hood 5. The conduit 8 is in unobstructed communication by wayof branch conduits 9, passages 10 in the press cross beam 1 and passages11 in the cooling plate 2, with a grate space 12 between the coolingplate and the heating plate 4. The passages 10 may be formed by means ofclosed hollow spaces of the cross beam construction with upper and lowerpassage apertures 13 (Fig. 1). The unobstructed communication betweenthe space 12 in which the grate is disposed and the hood 5 is madepossible by means ofnotches 14 in the bars of the grate 3.

The compressed gas conducted through the conduit 8, for examplecompressed air, as a rule needs onlyto be subject to a small excesspressure of a few millimetres of water. The gas flows through thepassages 11 into the center of the grate space lz'andspreads out in alldirections over this space through grate notches 14. Thus the noxiousgases coming out of the press space are prevented from penetrating intothe grate space 12.

I claim:

In a multi-stage press, in combination, at least one cross beam havingan upper horizontal member and a lower horizontal member spaced fromsaid upper member, both said members having apertures, a plurality ofspaced vertical walls connecting both said members and forming passagestherewith communicating with said aper-- and with atmosphere, conduitmeans connected with the apertures in, said upper member for introducingcompressed air into said passages and into said grate space, a. gasdischarge hood disposed above said crossbeam for withdrawing noxiousgases and having an exit duct, wherev by the pressure of compressed airprevents noxious gases from penetrating into the grate space.

References Cited in the file of this patent UNITED STATES PATENTS FranceNov. 18, 1953

